Table 6.
Stepwise multiple regression of composite expressive language abilities based on age equivalent scores from the Mullen, sequenced inventory of communication development (SICD), and Vineland for the autism, pervasive developmental disorders-not otherwise specified (PDD-NOS), and developmental delay (DD) groups using the predictors NV (nonverbal cognition), FVoc (frequency of vocalization), play, imitation, and joint attention (JA)
| Group | Step | B (SE) | β | p | R2 | ΔR2 |
|---|---|---|---|---|---|---|
| Autism | 1 NV | .458 (.067) | .598 | .000 | .358*** | |
| 2 NV | .436 (.064) | .569 | .000 | |||
| FVoc | −1.464 (.468) | −.261 | .002 | .425** | .067 | |
| 3 NV | .318 (.073) | .416 | .000 | |||
| FVoc | −1.761 (.459) | −.314 | .000 | |||
| Play | −1.455 (.493) | −.281 | .004 | .479** | .055 | |
| PDD-NOS | 1 NV | .551 (.098) | .654 | .000 | .428*** | |
| 2 NV | .456 (.092) | .541 | .000 | |||
| JA | −3.092 (.899) | −.376 | .001 | .556** | .128 | |
| DD | 1 NV | .648 (.104) | .705 | .000 | .498*** | |
| 2 NV | .398 (.140) | .434 | .007 | |||
| Imitation | −2.341 (.940) | −.380 | .017 | .568* | .070 |
*
p < .05,
**
p < .01,
***
p < .001